The present invention relates to an apparatus for automatically milking an animal comprising at least one teatcup having a teat entrance end, and a movable arm for moving said teatcup towards a teat of an animal to be milked and attaching it thereto.
An apparatus of this kind is known from WO 90/07268, which suggests that teatcups are brought to the teats of a cow by means of a robot arm. The teatcups are moved one at a time by means of the robot arm under the belly between the front and rear legs of the cow, and rearwards towards the udder.
An object of the invention is to improve the success rate of teatcup attachment.
This has been obtained by an apparatus of the initially defined kind, which is characterised in that the teat entrance end of said teatcup is arranged, while being moved by said movable arm towards said teat, to be held in relation to said movable arm at a level which is different from that of the teat entrance end of a further teatcup, when held in relation to said movable arm.
Hereby, it is not necessary to detach a teatcup on a front teat while re-attaching a teatcup, which has fallen off a rear teat in cases where the movable arm is moved towards the udder in a direction towards the rear of the cow.
Preferably, said movable arm is provided with an end portion, for holding a plurality of teatcups, wherein said at least one teatcup is held at a level, which is different from that of said further teatcup held by said end portion.
Suitably, said end portion is provided with a first part holding said at least one teatcup at a first level, and a second part holding said further teatcup at a second level. Hereby is achieved that the teatcups are allowed to be held at different levels.
Preferably, said first part of the end portion is arranged substantially parallel to said second part, said first and second parts being interconnected by an intermediate portion. Hereby, the teatcups are allowed to move between the different levels.
Suitably, said end portion is provided with a teatcup supplying means for moving a teatcup from said first part to said second part. Hereby, the teatcups are allowed to be actively moved between the different levels.
Preferably, said teatcup supplying means comprises a guide means and a supplying member, said supplying member being arranged to move at least one teatcup along said guide means towards said second part. In particular, said guide means comprises a pair of parallel guide members.
Suitably, said at least one teatcup and said further teatcup are arranged to co-operate with a connection means of said end portion in such a way, that they are held at different levels in relation to said end portion.
Preferably, said at least one teatcup and said farther teatcup are movable away from said end portion, independently from one another.
Suitably, said at least one teatcup has a longitudinal extension, and said further teatcup has a longitudinal extension, the longitudinal extension of said at least one teatcup being different from the longitudinal extension of said further teatcup. Hereby, different lengths of the teatcups are achieved.
Preferably, said at least one teatcup and said movable arm are provided with an identification means for allowing establishment of the identity of said at least one teatcup. Hereby, it is possible to determine which teatcup is to be or has been attached to a teat.
In particular, said at least one teatcup is provided with a bar code, and said movable arm is provided with a laser reader for reading said bar code. Hereby, a quick identification of the teatcup is achieved.
Suitably, said at least one teatcup is connectible to a vacuum source, a teat cleaning means being adapted to be connected at the teat entrance end of said at least one teatcup by means of a vacuum prevailing in the teatcup. Hereby, a teat cleaner is allowed to be fetched by the movable arm without the use of a gripper.
Suitably, the teat entrance end of said at least one teatcup is arranged at a higher level that the teat entrance end of the further teatcup, as seen in a vertical plane. Hereby, it is possible to apply a teatcup onto a rear teat, when a front teat has a teatcup attached thereonto.
Preferably, said movable arm is a service arm, which supplies one or more teatcups to a desired position, for allowing a robot arm with a gripper to grip a teatcup.
Alternatively, said movable arm is a robot arm.
Suitably, said robot arm is provided with laser sensor. Hereby, the position of a teat is possible to be located.
In particular, said laser sensor comprises a laser transmitter for forming a line, such as a scanning laser beam or a stable or scanning laser plane, and a laser reader, such as an image capturing device.
Suitably, said laser reader is adapted to read bar codes. Accordingly, the location of a teat and the identity of a teatcup with applied bar-codes is possible to be established by means of the same laser sensor.